yttrium

noun

yt·​tri·​um ˈi-trē-əm 

: a metallic element with atomic number 39 usually included in the rare-earth group that occurs usually with other rare earth elements in minerals and is used especially in phosphors, YAG lasers, alloys, and treatments for certain cancers see Chemical Elements Table

Examples of yttrium in a Sentence

Recent Examples on the Web

To explore the effect, the team used yttrium iron garnet, a ferrimagnetic insulator known for its long spin wave lifetime. —Aamir Khollam, Interesting Engineering, 29 Nov. 2025

The most common heavy rare-earth elements—dysporosium, terbium, and yttrium—are used in the heavy-duty magnets which power EV motors and military tech. —Eva Roytburg, Fortune, 18 Nov. 2025

Rare earths include 17 metallic elements in the periodic table made up of scandium, yttrium and the lanthanides. —Ramishah Maruf, CNN Money, 30 Oct. 2025

The analyst added that these permanent magnets use elements such as samarium-cobalt and neodymium-iron-boron molecules or yttrium, a rare earth metal used to prevent corrosion. —Lisa Kailai Han, CNBC, 13 Oct. 2025

Word History

Etymology

New Latin, from yttria yttrium oxide (Y₂O₃), irregular from Ytterby, town in southern Sweden

First Known Use

1814, in the meaning defined above

Kids Definition

yttrium

noun

yt·​tri·​um ˈi-trē-əm 

: a metallic element that occurs in minerals along with other similar uncommon elements see element

Medical Definition

yttrium

noun

yt·​tri·​um ˈi-trē-əm 

: a trivalent metallic element usually included among the rare earth elements which it resembles chemically and with which it occurs in minerals

—symbol Y see Chemical Elements Table